Add option to ensure cross-origin isolation headers on web export

misc/dist/html/full-size.html

@@ -218,8 +218,29 @@ const engine = new Engine(GODOT_CONFIG);
 		threads: GODOT_THREADS_ENABLED,
 	});
 	if (missing.length !== 0) {
+		if (GODOT_CONFIG['serviceWorker'] && GODOT_CONFIG['ensureCrossOriginIsolationHeaders'] && 'serviceWorker' in navigator) {
+			// There's a chance that installing the service worker would fix the issue
+			Promise.race([
+				navigator.serviceWorker.getRegistration().then((registration) => {
+					if (registration != null) {
+						return Promise.reject(new Error('Service worker already exists.'));
+					}
+					return registration;
+				}).then(() => engine.installServiceWorker()),
+				// For some reason, `getRegistration()` can stall
+				new Promise((resolve) => {
+					setTimeout(() => resolve(), 2000);
+				}),
+			]).catch((err) => {
+				console.error('Error while registering service worker:', err);
+			}).then(() => {
+				window.location.reload();
+			});
+		} else {
+			// Display the message as usual
 			const missingMsg = 'Error\nThe following features required to run Godot projects on the Web are missing:\n';
 			displayFailureNotice(missingMsg + missing.join('\n'));
+		}
 	} else {
 		setStatusMode('indeterminate');
 		engine.startGame({

misc/dist/html/service-worker.js

@@ -3,101 +3,163 @@
 // that they need an Internet connection to run the project if desired.
 // Incrementing CACHE_VERSION will kick off the install event and force
 // previously cached resources to be updated from the network.
-const CACHE_VERSION = "___GODOT_VERSION___";
-const CACHE_PREFIX = "___GODOT_NAME___-sw-cache-";
+/** @type {string} */
+const CACHE_VERSION = '___GODOT_VERSION___';
+/** @type {string} */
+const CACHE_PREFIX = '___GODOT_NAME___-sw-cache-';
 const CACHE_NAME = CACHE_PREFIX + CACHE_VERSION;
-const OFFLINE_URL = "___GODOT_OFFLINE_PAGE___";
+/** @type {string} */
+const OFFLINE_URL = '___GODOT_OFFLINE_PAGE___';
+/** @type {boolean} */
+const ENSURE_CROSSORIGIN_ISOLATION_HEADERS = ___GODOT_ENSURE_CROSSORIGIN_ISOLATION_HEADERS___;
 // Files that will be cached on load.
+/** @type {string[]} */
 const CACHED_FILES = ___GODOT_CACHE___;
 // Files that we might not want the user to preload, and will only be cached on first load.
+/** @type {string[]} */
 const CACHABLE_FILES = ___GODOT_OPT_CACHE___;
 const FULL_CACHE = CACHED_FILES.concat(CACHABLE_FILES);
 
-self.addEventListener("install", (event) => {
-	event.waitUntil(caches.open(CACHE_NAME).then(cache => cache.addAll(CACHED_FILES)));
+self.addEventListener('install', (event) => {
+	event.waitUntil(caches.open(CACHE_NAME).then((cache) => cache.addAll(CACHED_FILES)));
 });
 
-self.addEventListener("activate", (event) => {
+self.addEventListener('activate', (event) => {
 	event.waitUntil(caches.keys().then(
 		function (keys) {
 			// Remove old caches.
-			return Promise.all(keys.filter(key => key.startsWith(CACHE_PREFIX) && key != CACHE_NAME).map(key => caches.delete(key)));
-		}).then(function () {
+			return Promise.all(keys.filter((key) => key.startsWith(CACHE_PREFIX) && key !== CACHE_NAME).map((key) => caches.delete(key)));
+		}
+	).then(function () {
 		// Enable navigation preload if available.
-			return ("navigationPreload" in self.registration) ? self.registration.navigationPreload.enable() : Promise.resolve();
-		})
-	);
+		return ('navigationPreload' in self.registration) ? self.registration.navigationPreload.enable() : Promise.resolve();
+	}));
 });
 
-async function fetchAndCache(event, cache, isCachable) {
+/**
+ * Ensures that the response has the correct COEP/COOP headers
+ * @param {Response} response
+ * @returns {Response}
+ */
+function ensureCrossOriginIsolationHeaders(response) {
+	if (response.headers.get('Cross-Origin-Embedder-Policy') === 'require-corp'
+		&& response.headers.get('Cross-Origin-Opener-Policy') === 'same-origin') {
+		return response;
+	}
+
+	const crossOriginIsolatedHeaders = new Headers(response.headers);
+	crossOriginIsolatedHeaders.set('Cross-Origin-Embedder-Policy', 'require-corp');
+	crossOriginIsolatedHeaders.set('Cross-Origin-Opener-Policy', 'same-origin');
+	const newResponse = new Response(response.body, {
+		status: response.status,
+		statusText: response.statusText,
+		headers: crossOriginIsolatedHeaders,
+	});
+
+	return newResponse;
+}
+
+/**
+ * Calls fetch and cache the result if it is cacheable
+ * @param {FetchEvent} event
+ * @param {Cache} cache
+ * @param {boolean} isCacheable
+ * @returns {Response}
+ */
+async function fetchAndCache(event, cache, isCacheable) {
 	// Use the preloaded response, if it's there
+	/** @type { Response } */
 	let response = await event.preloadResponse;
-	if (!response) {
+	if (response == null) {
 		// Or, go over network.
 		response = await self.fetch(event.request);
 	}
-	if (isCachable) {
+
+	if (ENSURE_CROSSORIGIN_ISOLATION_HEADERS) {
+		response = ensureCrossOriginIsolationHeaders(response);
+	}
+
+	if (isCacheable) {
 		// And update the cache
 		cache.put(event.request, response.clone());
 	}
+
 	return response;
 }
 
-self.addEventListener("fetch", (event) => {
-	const isNavigate = event.request.mode === "navigate";
-	const url = event.request.url || "";
-	const referrer = event.request.referrer || "";
-	const base = referrer.slice(0, referrer.lastIndexOf("/") + 1);
-	const local = url.startsWith(base) ? url.replace(base, "") : "";
-	const isCachable = FULL_CACHE.some(v => v === local) || (base === referrer && base.endsWith(CACHED_FILES[0]));
+self.addEventListener(
+	'fetch',
+	/**
+	 * Triggered on fetch
+	 * @param {FetchEvent} event
+	 */
+	(event) => {
+		const isNavigate = event.request.mode === 'navigate';
+		const url = event.request.url || '';
+		const referrer = event.request.referrer || '';
+		const base = referrer.slice(0, referrer.lastIndexOf('/') + 1);
+		const local = url.startsWith(base) ? url.replace(base, '') : '';
+		const isCachable = FULL_CACHE.some((v) => v === local) || (base === referrer && base.endsWith(CACHED_FILES[0]));
 		if (isNavigate || isCachable) {
-		event.respondWith(async function () {
+			event.respondWith((async () => {
 				// Try to use cache first
 				const cache = await caches.open(CACHE_NAME);
-			if (event.request.mode === "navigate") {
+				if (isNavigate) {
 					// Check if we have full cache during HTML page request.
-				const fullCache = await Promise.all(FULL_CACHE.map(name => cache.match(name)));
-				const missing = fullCache.some(v => v === undefined);
+					/** @type {Response[]} */
+					const fullCache = await Promise.all(FULL_CACHE.map((name) => cache.match(name)));
+					const missing = fullCache.some((v) => v === undefined);
 					if (missing) {
 						try {
 							// Try network if some cached file is missing (so we can display offline page in case).
-						return await fetchAndCache(event, cache, isCachable);
+							const response = await fetchAndCache(event, cache, isCachable);
+							return response;
 						} catch (e) {
 							// And return the hopefully always cached offline page in case of network failure.
-						console.error("Network error: ", e);
-						return await caches.match(OFFLINE_URL);
+							console.error('Network error: ', e); // eslint-disable-line no-console
+							return caches.match(OFFLINE_URL);
 						}
 					}
 				}
-			const cached = await cache.match(event.request);
-			if (cached) {
+				let cached = await cache.match(event.request);
+				if (cached != null) {
+					if (ENSURE_CROSSORIGIN_ISOLATION_HEADERS) {
+						cached = ensureCrossOriginIsolationHeaders(cached);
+					}
 					return cached;
-			} else {
+				}
 				// Try network if don't have it in cache.
-				return await fetchAndCache(event, cache, isCachable);
+				const response = await fetchAndCache(event, cache, isCachable);
+				return response;
+			})());
+		} else if (ENSURE_CROSSORIGIN_ISOLATION_HEADERS) {
+			event.respondWith((async () => {
+				let response = await fetch(event.request);
+				response = ensureCrossOriginIsolationHeaders(response);
+				return response;
+			})());
 		}
-		}());
 	}
-});
+);
 
-self.addEventListener("message", (event) => {
+self.addEventListener('message', (event) => {
 	// No cross origin
-	if (event.origin != self.origin) {
+	if (event.origin !== self.origin) {
 		return;
 	}
-	const id = event.source.id || "";
-	const msg = event.data || "";
+	const id = event.source.id || '';
+	const msg = event.data || '';
 	// Ensure it's one of our clients.
 	self.clients.get(id).then(function (client) {
 		if (!client) {
 			return; // Not a valid client.
 		}
-		if (msg === "claim") {
+		if (msg === 'claim') {
 			self.skipWaiting().then(() => self.clients.claim());
-		} else if (msg === "clear") {
+		} else if (msg === 'clear') {
 			caches.delete(CACHE_NAME);
-		} else if (msg === "update") {
-			self.skipWaiting().then(() => self.clients.claim()).then(() => self.clients.matchAll()).then(all => all.forEach(c => c.navigate(c.url)));
+		} else if (msg === 'update') {
+			self.skipWaiting().then(() => self.clients.claim()).then(() => self.clients.matchAll()).then((all) => all.forEach((c) => c.navigate(c.url)));
 		} else {
 			onClientMessage(event);
 		}

platform/web/.eslintrc.sw.js

@@ -0,0 +1,14 @@
+module.exports = {
+	"extends": [
+		"./.eslintrc.js",
+	],
+	"rules": {
+		"no-restricted-globals": 0,
+	},
+	"globals": {
+		"onClientMessage": true,
+		"___GODOT_ENSURE_CROSSORIGIN_ISOLATION_HEADERS___": true,
+		"___GODOT_CACHE___": true,
+		"___GODOT_OPT_CACHE___": true,
+	},
+};

platform/web/doc_classes/EditorExportPlatformWeb.xml

@@ -35,6 +35,10 @@
 		</member>
 		<member name="progressive_web_app/enabled" type="bool" setter="" getter="">
 		</member>
+		<member name="progressive_web_app/ensure_cross_origin_isolation_headers" type="bool" setter="" getter="">
+			When enabled, the progressive web app will make sure that each request has cross-origin isolation headers (COEP/COOP).
+			This can simplify the setup to serve the exported game.
+		</member>
 		<member name="progressive_web_app/icon_144x144" type="String" setter="" getter="">
 		</member>
 		<member name="progressive_web_app/icon_180x180" type="String" setter="" getter="">

platform/web/export/export_plugin.cpp

@@ -150,6 +150,7 @@ void EditorExportPlatformWeb::_fix_html(Vector<uint8_t> &p_html, const Ref<Edito
 	config["executable"] = p_name;
 	config["args"] = args;
 	config["fileSizes"] = p_file_sizes;
+	config["ensureCrossOriginIsolationHeaders"] = (bool)p_preset->get("progressive_web_app/ensure_cross_origin_isolation_headers");
 
 	String head_include;
 	if (p_preset->get("html/export_icon")) {
@@ -222,10 +223,12 @@ Error EditorExportPlatformWeb::_build_pwa(const Ref<EditorExportPreset> &p_prese
 	const String dir = p_path.get_base_dir();
 	const String name = p_path.get_file().get_basename();
 	bool extensions = (bool)p_preset->get("variant/extensions_support");
+	bool ensure_crossorigin_isolation_headers = (bool)p_preset->get("progressive_web_app/ensure_cross_origin_isolation_headers");
 	HashMap<String, String> replaces;
 	replaces["___GODOT_VERSION___"] = String::num_int64(OS::get_singleton()->get_unix_time()) + "|" + String::num_int64(OS::get_singleton()->get_ticks_usec());
 	replaces["___GODOT_NAME___"] = proj_name.substr(0, 16);
 	replaces["___GODOT_OFFLINE_PAGE___"] = name + ".offline.html";
+	replaces["___GODOT_ENSURE_CROSSORIGIN_ISOLATION_HEADERS___"] = ensure_crossorigin_isolation_headers ? "true" : "false";
 
 	// Files cached during worker install.
 	Array cache_files;
@@ -353,6 +356,7 @@ void EditorExportPlatformWeb::get_export_options(List<ExportOption> *r_options)
 	r_options->push_back(ExportOption(PropertyInfo(Variant::BOOL, "html/focus_canvas_on_start"), true));
 	r_options->push_back(ExportOption(PropertyInfo(Variant::BOOL, "html/experimental_virtual_keyboard"), false));
 	r_options->push_back(ExportOption(PropertyInfo(Variant::BOOL, "progressive_web_app/enabled"), false));
+	r_options->push_back(ExportOption(PropertyInfo(Variant::BOOL, "progressive_web_app/ensure_cross_origin_isolation_headers"), true));
 	r_options->push_back(ExportOption(PropertyInfo(Variant::STRING, "progressive_web_app/offline_page", PROPERTY_HINT_FILE, "*.html"), ""));
 	r_options->push_back(ExportOption(PropertyInfo(Variant::INT, "progressive_web_app/display", PROPERTY_HINT_ENUM, "Fullscreen,Standalone,Minimal UI,Browser"), 1));
 	r_options->push_back(ExportOption(PropertyInfo(Variant::INT, "progressive_web_app/orientation", PROPERTY_HINT_ENUM, "Any,Landscape,Portrait"), 0));

platform/web/js/engine/engine.js

@@ -179,9 +179,7 @@ const Engine = (function () {
 							preloader.preloadedFiles.length = 0; // Clear memory
 							me.rtenv['callMain'](me.config.args);
 							initPromise = null;
-							if (me.config.serviceWorker && 'serviceWorker' in navigator) {
-								navigator.serviceWorker.register(me.config.serviceWorker);
-							}
+							me.installServiceWorker();
 							resolve();
 						});
 					});
@@ -242,6 +240,17 @@ const Engine = (function () {
 					this.rtenv['request_quit']();
 				}
 			},
+
+			/**
+			 * Install the progressive-web app service worker.
+			 * @returns {Promise} The service worker registration promise.
+			 */
+			installServiceWorker: function () {
+				if (this.config.serviceWorker && 'serviceWorker' in navigator) {
+					return navigator.serviceWorker.register(this.config.serviceWorker);
+				}
+				return Promise.resolve();
+			},
 		};
 
 		Engine.prototype = proto;
@@ -252,6 +261,7 @@ const Engine = (function () {
 		Engine.prototype['startGame'] = Engine.prototype.startGame;
 		Engine.prototype['copyToFS'] = Engine.prototype.copyToFS;
 		Engine.prototype['requestQuit'] = Engine.prototype.requestQuit;
+		Engine.prototype['installServiceWorker'] = Engine.prototype.installServiceWorker;
 		// Also expose static methods as instance methods
 		Engine.prototype['load'] = Engine.load;
 		Engine.prototype['unload'] = Engine.unload;

platform/web/package.json

@@ -5,18 +5,20 @@
   "description": "Development and linting setup for Godot's Web platform code",
   "scripts": {
     "docs": "jsdoc --template js/jsdoc2rst/ js/engine/engine.js js/engine/config.js js/engine/features.js --destination ''",
-    "lint": "npm run lint:engine && npm run lint:libs && npm run lint:modules && npm run lint:tools && npm run lint:html",
+    "lint": "npm run lint:engine && npm run lint:libs && npm run lint:modules && npm run lint:tools && npm run lint:sw && npm run lint:html",
     "lint:engine": "eslint \"js/engine/*.js\" --no-eslintrc -c .eslintrc.engine.js",
+    "lint:sw": "eslint \"../../misc/dist/html/service-worker.js\" --no-eslintrc -c .eslintrc.sw.js",
     "lint:libs": "eslint \"js/libs/*.js\" --no-eslintrc -c .eslintrc.libs.js",
     "lint:modules": "eslint \"../../modules/**/*.js\" --no-eslintrc -c .eslintrc.libs.js",
     "lint:tools": "eslint \"js/jsdoc2rst/**/*.js\" --no-eslintrc -c .eslintrc.engine.js",
     "lint:html": "eslint \"../../misc/dist/html/*.html\" --no-eslintrc -c .eslintrc.html.js",
-    "format": "npm run format:engine && npm run format:libs && npm run format:modules && npm run format:tools && npm run format:html",
+    "format": "npm run format:engine && npm run format:libs && npm run format:modules && npm run format:tools && format:sw && npm run format:html",
     "format:engine": "npm run lint:engine -- --fix",
     "format:libs": "npm run lint:libs -- --fix",
     "format:modules": "npm run lint:modules -- --fix",
     "format:tools": "npm run lint:tools -- --fix",
-    "format:html": "npm run lint:html -- --fix"
+    "format:html": "npm run lint:html -- --fix",
+    "format:sw": "npm run lint:sw -- --fix"
   },
   "author": "Godot Engine contributors",
   "license": "MIT",